Dark box apparatus for fluoroscopy, fluoroscopy system, and fluoroscopy method

ABSTRACT

Noise in a fluorescence image acquired during fluoroscopy is eliminated to present a clear fluorescence image, and the relative positional relationship between the fluoroscopy unit and the specimen can be recognized even while fluoroscopy is in progress. A dark box apparatus for fluoroscopy includes: a dark-box main body enclosing a specimen and a fluoroscopy unit for illuminating the specimen with excitation light with a first spectral band and for detecting fluorescence with a second spectral band generated by the specimen; an illumination light source disposed in the dark-box main body to emit light with a third spectral band different from the first spectral band and the second spectral band; and an observation window disposed in the dark-box main body, the observation window being capable of transmitting light with a fourth spectral band which includes at least part of the third spectral band and does not include the first spectral band and the second spectral band.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to dark box apparatuses for fluoroscopy,fluoroscopy systems, and fluoroscopy methods.

This application is based on Japanese Patent Applications No.2004-257240, the contents of which are incorporated herein by reference.

2. Description of Related Art

As a technique for non-invasively examining the interior of a specimen,some known confocal microscopes or multiphoton-excitation microscopesemploy a fluoroscopy method for illuminating a specimen with excitationlight, such as a laser beam, to examine fluorescence generated by thespecimen.

However, since fluorescence generated by a specimen is very weak, it isdifficult to acquire a clear fluorescence image due to external noise iffluoroscopy is performed in the presence of extraneous light. For thisreason, if fluoroscopy is to be performed in a darkroom, a specimen isfirst positioned with respect to the microscope apparatus under externallight, and then the specimen is illuminated with excitation light withall extraneous light blocked to detect fluorescence emitted from thespecimen.

Though in a totally different technical field, a so-called dark-placeobservation device for examining the influence of particular wavelengthsof light upon plants in a place dark enough to prevent the plants frombeing affected by light is also known (e.g., see Japanese UnexaminedPatent Application Publication No. 2002-369624).

For examination with these known dark-place observation devices, plantsare first positioned in a dark box completely protected from extraneouslight to prevent the plants from experiencing biological effects, suchas gene expression, due to extraneous light, and then an infrared lightsource emitting infrared light with wavelengths that do not affect theplants and an infrared CCD camera are placed in the dark box to observean image from the infrared CCD camera on a monitor outside the dark box.

If fluoroscopy is to be performed in a darkroom such that a specimen isfirst positioned with respect to the microscope apparatus underextraneous light and then the specimen is illuminated with excitationlight with all extraneous light blocked to detect fluorescence emittedfrom the specimen, unsuccessful positioning of the specimen, such as ashift of the specimen from the desired examination position, may occur.In this case, the positional relationship between the microscopeapparatus and the specimen needs to be re-adjusted. Thus, the positionalrelationship between the microscope and the specimen may need to beadjusted by feeling with the hands in a darkroom where extraneous lightis blocked. This may cause the objective lens of the microscopeapparatus to interfere with the specimen, possibly damaging theobjective lens or the specimen. In addition, repeating the procedure ofintroducing extraneous light for positioning and then blocking theextraneous light again for examination is time-consuming and annoying.

BRIEF SUMMARY OF THE INVENTION

The present invention has been conceived in light of thesecircumstances, and it is an object of the present invention to provide adark box apparatus for fluoroscopy, a fluoroscopy system, and afluoroscopy method for eliminating noise in a fluorescence imageacquired during fluoroscopy to present a clear fluorescence image andfor checking the relative positional relationship between thefluoroscopy unit and the specimen even while fluoroscopy is in progress.

In order to achieve the above-described objects, the present inventionprovides the following solutions.

According to a first aspect of the present invention, a dark boxapparatus for fluoroscopy includes: a dark-box main body enclosing aspecimen and a fluoroscopy unit for illuminating the specimen withexcitation light with a first spectral band and for detectingfluorescence with a second spectral band generated by the specimen; anillumination light source disposed in the dark-box main body to emitlight with a third spectral band different from the first spectral bandand the second spectral band; and an observation window disposed on thedark-box main body, the observation window being capable of transmittinglight with a fourth spectral band which includes at least part of thethird spectral band and does not include the first spectral band and thesecond spectral band.

According to this aspect, when fluoroscopy is to be performed by placingthe specimen and the fluoroscopy unit in the dark-box main body andradiating excitation light with the first spectral band to detectfluorescence with the second spectral band emitted from the specimen,the illumination light source is operated in the dark-box main body toemit visible light with the third spectral band. Since the observationwindow provided in the dark-box main body can transmit light with thefourth spectral band including at least part of the third spectral band,part of light with the third spectral band reflected at the specimen andthe fluoroscopy unit passes through the observation window and isobserved by an external observer.

In other words, the observer can easily recognize the state of thespecimen, the positional relationship between the specimen and thefluoroscopy unit, etc. in the dark-box main body with the aid of lightwith the third spectral band coming through the observation window. Onthe other hand, since the third spectral band differs from the firstspectral band, even if light with the third spectral band is emitted inthe dark-box main body, the fluorescent material of the specimen is notexcited with the emitted visible light with the third spectral band.Furthermore, since the third spectral band differs from the secondspectral band, light with the third spectral band emitted in thedark-box main body is not detected by the fluoroscopy unit, and hencenoise in the acquired fluorescence image does not increase.

Since the observation window transmits light with the fourth spectralband, light with the fourth spectral band may enter the dark-box mainbody from outside the dark-box main body. However, since the fourthspectral band does not include the first spectral band and the secondspectral band, the fluorescent material is not excited by light enteringthe dark-box main body or noise in the fluorescence image does notincrease, just like in the above-described case. On the other hand, theobservation window transmits at least part of other light with the thirdspectral band from outside the dark-box main body. This transmittedlight can be used as illumination light along with the light from theillumination light source.

In the above-described aspect, it is preferable that the illuminationlight source be disposed at a location such that the illumination lightsource is not directly visible from outside through the observationwindow.

In this manner, the observer observing from outside the dark-box mainbody through the observation window does not look directly at theillumination light source. This prevents light of the illumination lightsource from dazzling the observer. More specifically, the illuminationlight source may be provided out of the field of view of the observationwindow or alternatively, a baffle plate etc. may be provided to preventlight from the illumination light source from directly reaching theobservation window.

According to a second aspect of the present invention, a dark boxapparatus for fluoroscopy includes: a dark-box main body for blockingentry of extraneous light by enclosing a specimen and a fluoroscopy unitfor illuminating the specimen with excitation light with a firstspectral band and for detecting fluorescence with a second spectral bandgenerated by the specimen; an illumination light source disposed in thedark-box main body to emit light with a third spectral band differentfrom the first spectral band and the second spectral band; a photographyunit disposed in the dark-box main body to photograph the specimenilluminated by the illumination light source and the fluoroscopy unit;and an image display unit disposed outside the dark-box main body todisplay an image acquired by the photography unit.

According to this aspect, when the specimen and the fluoroscopy unit areplaced in the dark-box main body and excitation light with the firstspectral band is radiated to perform fluoroscopy for detectingfluorescence with the second spectral band emitted from the specimen,the illumination light source is operated in the dark-box main body toradiate light with the third spectral band. Light with the thirdspectral band is radiated onto the specimen and the fluoroscopy unit andis photographed by the photography unit provided in the dark-box mainbody. An acquired image is displayed on the image display unit outsidethe dark-box main body. The observer can easily recognize the state ofthe specimen, the positional relationship between the specimen and thefluoroscopy unit, etc. by observing on the image display unit thespecimen and the fluoroscopy unit illuminated with light with the thirdspectral band.

On the other hand, since the third spectral band differs from the firstspectral band, even if light with the third spectral band is emitted inthe dark-box main body, the fluorescent material of the specimen is notexcited with the emitted light with the third spectral band.Furthermore, since the third spectral band differs from the secondspectral band, light with the third spectral band emitted in thedark-box main body is not detected by the fluoroscopy unit, and hencenoise in the acquired fluorescence image does not increase.

In the above-described aspect, it is preferable that the illuminationlight source be disposed at a location such that light emitted from theillumination light source is not directly incident upon the photographyunit.

In this manner, an image acquired by the photography unit can be free ofnoise, such as flare, due to light from the illumination light source.Therefore, light from the illumination light source does not interferewith the observation. More specifically, the illumination light sourcemay be provided out of the field of view of the photography unit oralternatively, a baffle plate etc. may be provided to prevent light fromthe illumination light source from being directly incident upon thephotography unit.

In the above-described aspect, a camera including the photography unitand the image display unit may be provided on a wall surface of thedark-box main body such that the photography unit faces inward and theimage display unit faces outward.

In this manner, an image which would appear if the interior of the darkbox were observed through the observation window can be displayed on theimage display unit.

In the above-described aspect, a bellows member may be provided betweenthe wall surface of the dark-box main body and the camera such that thebellows member supports the camera so that the camera is movablerelative to the wall surface.

In this manner, the image display range on the image display unit caneasily be adjusted by moving the camera with respect to the wall surfacethrough deformation of the bellows member.

In the above-described aspect, the illumination light source may includea wavelength-switching mechanism for switching a spectral band ofemitted light.

When examination is to be performed using the fluoroscopy unit with thewavelength of the excitation light switched, the wavelength-switchingmechanism is operated to switch the spectral band of light to be emittedby the illumination light source, thereby allowing the wavelength of theexcitation light to be selected more flexibly.

According to a third aspect of the present invention, a fluoroscopysystem includes: a fluoroscopy unit for illuminating a specimen withexcitation light with a first spectral band and for detectingfluorescence with a second spectral band generated by the specimen; andone of the above-described dark box apparatuses for fluoroscopy, whereinthe dark-box main body includes: a door for opening and closing thedark-box main body; an open/closed sensor for detecting an open/closedstate of the door; and an excitation-light control section for stoppingemission of excitation light from the fluoroscopy unit when theopen/closed sensor detects that the door is opened.

According to this aspect, the specimen and the fluoroscopy unit areplaced in the dark-box main body, the door is closed, excitation lightwith the first spectral band is radiated onto the specimen in thefluoroscopy unit, and fluorescence with the second spectral band emittedfrom the specimen is detected to perform fluoroscopy. If the door isopened for some reason during fluoroscopy, the open/closed sensordetects an open state of the door and emission of excitation light inthe fluoroscopy unit is stopped by the operation of the excitation lightcontrol section. As a result, the excitation light is prevented fromleaking from the dark box.

Furthermore, when the open/closed sensor detects a closed state of thedoor, excitation light is emitted by the operation of the excitationlight control section. As a result, fluoroscopy is performed while lightserving as noise from outside the dark box is blocked. This provides aclear fluorescence image with less noise.

According to a fourth aspect of the present invention, a fluoroscopysystem includes: a fluoroscopy unit for illuminating a specimen withexcitation light with a first spectral band and for detectingfluorescence with a second spectral band generated by the specimen; andone of the above-described dark box apparatuses for fluoroscopy, whereinthe dark-box main body includes: a door for opening and closing thedark-box main body; an open/closed sensor for detecting an open/closedstate of the door; and an operation control section for decreasing anoperation speed of the fluoroscopy unit when the open/closed sensordetests that the door is closed.

According to this aspect, the door of the dark-box main body is opened,the specimen is positioned with respect to the fluoroscopy unit,preparations are made for rough alignment of the focal position of thefluoroscopy unit, and then the door is closed to arrange the specimenand the fluoroscopy unit in the dark-box main body. In this state,fluoroscopy is performed by radiating excitation light with the firstspectral band onto the specimen in the fluoroscopy unit while thepositional relationship between the specimen and the fluoroscopy unit isfinely adjusted under light with the third spectral band from theillumination light source to detect fluorescence with the secondspectral band emitted from the specimen. In this case, according to thepresent invention, the operation of the operation control section causesthe fluoroscopy unit to operate at a lower operation speed while theopen/closed sensor detects a closed state of the door compared to whenthe open/closed sensor detects an open state of the door. As a result,it is possible to reduce the risk of the fluoroscopy unit mistakenlyinterfering with the specimen in the dark-box main body because onlylimited information is obtained through the observation window or theimage display unit. Therefore, damage to the fluoroscopy unit and thespecimen can be avoided.

According to a fifth aspect of the present invention, a fluoroscopymethod for emitting excitation light with a first spectral band from afluoroscopy unit onto a specimen and for examining fluorescence with asecond spectral band emitted from the specimen, the method includessteps of: enclosing the specimen and the fluoroscopy unit with a darkbox; emitting light with a third spectral band different from the firstspectral band and the second spectral band in the dark box; andmanipulating the specimen or the fluoroscopy unit from outside the darkbox while observing light with the third spectral band outside the darkbox through an observation window, disposed in the dark box, capable oftransmitting light with a fourth spectral band which includes at leastpart of the third spectral band and does not include the first spectralband and the second spectral band or through a photography unit disposedin the dark box.

According to this aspect, the fluoroscopy unit and the specimen areirradiated with light with the third spectral band to carry outexamination through the observation window or the photography unit.Therefore, the positional relationship between the fluoroscopy unit andthe specimen can easily be recognized in the dark box for reliableoperation without disturbing fluoroscopy with the fluoroscopy unit.Therefore, blind operation is eliminated, and hence an annoying repeatedprocedure of turning ON and OFF the illuminating light in the darkroomcan be avoided.

According to the present invention, since the fluoroscopy unit and thespecimen are irradiated with light with the third spectral banddifferent from the first and second spectral bands for examinationthrough the observation window or the photography unit, the positionalrelationship between the fluoroscopy unit and the specimen can easily berecognized in the dark box for reliable operation without disturbingfluoroscopy with the fluoroscopy unit. Therefore, blind operation iseliminated, and hence an annoying repeated procedure of turning ON andOFF the illuminating light in the darkroom can be avoided.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a dark box apparatus forfluoroscopy according to a first embodiment of the present invention.

FIG. 2 is a diagram depicting a spectral band of fluorescence inresponse to light from an illumination light source of the dark boxapparatus for fluoroscopy shown in FIG. 1 and the transmittancecharacteristic of an observation window.

FIG. 3 is a longitudinal sectional view of a dark box apparatus forfluoroscopy according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a modification of the darkbox apparatus for fluoroscopy shown in FIG. 3.

FIG. 5 is a longitudinal sectional view of a fluoroscopy systemaccording to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a modification of thefluoroscopy system shown in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

A dark box apparatus for fluoroscopy 1 according to a first embodimentof the present invention will now be described with reference to FIGS. 1and 2.

Referring to FIG. 1, the dark box apparatus for fluoroscopy 1 accordingto this embodiment includes a dark-box main body 2; an illuminationlight source 3 arranged in the dark-box main body 2; and an observationwindow 4 arranged in a wall surface 2 a of the dark-box main body 2.

The above-described dark-box main body 2 is a box member composed of amaterial blocking light of all wavelengths, and is large enough tocompletely contain an examination head 6 of a fluoroscopy unit 5, to bedescribed below; a raising-and-lowering mechanism 7 for raising andlowering the examination head 6; a specimen A; and a stage 8 holding thespecimen A for moving the specimen A two-dimensionally in the horizontaldirection or tilting the specimen A.

As shown in FIG. 1, the fluoroscopy unit 5 includes an optical unit 9;the examination head 6; and an optical fiber 10 for connecting theoptical unit 9 and the examination head 6.

The optical unit 9 includes an excitation light source 11 emittingexcitation light L1 with a first spectral band B1 (e.g., a wavelength of545 nm), such as a laser beam; a collimating lens 12 for converting theemitted excitation light L1 into collimated light; a coupling lens 13for focusing the excitation light L1 converted into collimated lightonto an end surface 10 a of the optical fiber 10; a dichroic mirror 14for separating fluorescence L2 with a second spectral band B2 (e.g., awavelength of 550 nm) from return light returning through the opticalfiber 10; a focusing lens 15 for focusing the separated fluorescence L2;and a photodetector 16 for detecting the focused fluorescence L2. Thephotodetector 16 is realized by, for example, a photomultiplier tube(PMT).

The examination head 6 includes a casing 17 which includes a collimatinglens 18 for converting the excitation light L1 from the excitation lightsource 11 into collimated light; an optical-scanning section 19performing two-dimensional scanning of the collimated light transmittedfrom the collimating lens 18; a pupil-projection lens 20 for forming anintermediate image by focusing the scanned excitation light L1; and animaging lens 21 for converting the excitation light L1 of theintermediate image into collimated light. The casing 17 further includesan objective lens 22 for focusing the excitation light L1 from theimaging lens 21 to re-form an image at a predetermined focal position.

The optical-scanning section 19 is realized by, for example, so-calledproximity galvano mirrors, which are two galvano mirrors 19 a and 19 barranged so as to oppose each other and which are rockable aboutmutually orthogonal axes.

The raising-and-lowering mechanism 7 supporting the examination head 6such that the examination head 6 can be raised and lowered includes araising-and-lowering slider 25 which can be raised and lowered by adriving device (not shown) in a support stand 24 extending verticallyfrom a base 23. The driving device can be operated from outside thedark-box main body 2 through remote operation.

The above-described illumination light source 3 is realized by, forexample, an argon laser light source emitting visible light L3 with athird spectral band B3 in the vicinity of, for example, 458 nm.

As shown in FIG. 1, the observation window 4 is provided on a tiltedsurface in the front of the dark-box main body 2, namely, on the tiltedsurface constituting part of the wall surface 2 a of the dark-box mainbody 2. Through the observation window 4, the examination head 6 of thefluoroscopy unit 5, which is arranged on the other side of the wallsurface 2 a of the dark-box main body 2, and the specimen A are in thefield of view.

Referring to FIG. 2, the observation window 4 blocks the excitationlight L1 with the first spectral band B1 emitted from the excitationlight source 11 of the fluoroscopy unit 5 and the fluorescence L2 withthe second spectral band B2 emitted from the specimen A, whiletransmitting the visible light L3 with the third spectral band B3emitted from the illumination light source 3. In short, the observationwindow 4 is characterized by transmitting light with wavelengths shorterthan 480 nm and blocking light with wavelengths of 480 nm and longer.

In this embodiment, the dark-box main body 2 further includes a baffleplate 26 arranged between the observation window 4 and the illuminationlight source 3. The baffle plate 26 is arranged to block theillumination light source 3 from the observation window 4, thuspreventing the illumination light source 3 from being viewed directlythrough the observation window 4.

A fluoroscopy method using the dark box apparatus for fluoroscopy 1according to this embodiment, with the above-described structure, willnow be described.

In order to perform fluoroscopy of the specimen A using the dark boxapparatus for fluoroscopy 1 according to this embodiment, first theexcitation light source 11 of the fluoroscopy unit 5 is turned OFF, thespecimen A is immobilized on the stage 8 outside the dark-box main body2, and the raising-and-lowering mechanism 7 is operated to roughlyposition the objective lens 22 of the examination head 6 with respect tothe specimen A. In this state, the specimen A, the examination head 6,the stage 8, and the raising-and-lowering mechanism 7 are placed in thedark-box main body 2. The dark-box main body 2 may be constructed so asto enclose the specimen A, the examination head 6, etc. Alternatively,the dark-box main body 2 may have a door, as described in anotherembodiment later, so that the examination head 6 and other members areenclosed by closing this door.

Next, the illumination light source 3 is operated to emit the visiblelight L3 with the third spectral band B3 in the dark-box main body 2.The visible light L3 with the third spectral band B3 is radiated ontothe objective lens 22 of the examination head 6 in the dark-box mainbody 2 and the specimen A opposed to the objective lens 22. Part of thevisible light L3 with the third spectral band B3 reflected at theobjective lens 22 and the specimen A goes out of the dark-box main body2 through the observation window 4.

Therefore, outside the dark-box main body 2, the observer can observethe visible light L3 with the third spectral band B3 transmitted throughthe observation window 4 to clearly learn the positional relationshipbetween the objective lens 22 and the specimen A, as well as the stateof the specimen A in the dark-box main body 2.

Based on this positional relationship between the objective lens 22 andthe specimen A observed through the observation window 4, the observeroperates the raising-and-lowering mechanism 7 and the stage 8 throughremote operation from outside the dark-box main body 2 to adjust thepositional relationship.

Next, the fluoroscopy unit 5 is operated to emit the excitation light L1with the first spectral band B1 from the excitation light source 11. Theexcitation light L1 is guided into the examination head 6 in thedark-box main body 2 via the optical fiber 10. The excitation light L1guided into the examination head 6 is converted into collimated light bythe collimating lens 18, is two-dimensionally scanned by theoptical-scanning section 19, and is re-focused onto the specimen Athrough the pupil-projection lens 20, the imaging lens 21, and theobjective lens 22.

When the specimen A is irradiated with the excitation light L1,fluorescent material in the specimen A or a fluorescent agent that hasbeen pre-administered to the specimen A is excited to emit thefluorescence L2 with the second spectral band B2. The emittedfluorescence L2 enters an end surface 10 b of the optical fiber 10through the objective lens 22, the imaging lens 21, the pupil-projectionlens 20, the optical-scanning section 19, and the collimating lens 18.

Since the end surface 10 b of the optical fiber 10 is arranged to have aconjugate positional relationship with the focal position of theobjective lens 22, only the fluorescence L2 generated near the focalposition of the objective lens 22, from among the fluorescence L2returning from the specimen A, enters the end surface 10 b of opticalfiber 10 and is returned to the optical unit 9. The fluorescence L2returned to the optical unit 9 is converted into collimated light by thecoupling lens 13, separated from the light path by the dichroic mirror14, focused by the focusing lens 15, and finally detected by thephotodetector 16.

The excitation light L1 is two-dimensionally scanned at the focalposition of the objective lens 22 through the operation of theoptical-scanning section 19. In this manner, a clear two-dimensionalfluorescence image can be acquired by detecting the fluorescence L2 fromeach position of the specimen A with the photodetector 16.

According to the dark box apparatus for fluoroscopy 1 of thisembodiment, the third spectral band B3 of the visible light L3 from theillumination light source 3 differs from the first spectral band B1 ofthe excitation light L1 and the second spectral band B2 of thefluorescence L2. Therefore, even if the visible light L3 is emitted fromthe illumination light source 3 onto the specimen A during fluoroscopy,the fluorescent material in the specimen A is not excited. Furthermore,even if the visible light L3 with the third spectral band B3 reflectedat the specimen A enters the detection light path of the fluorescence L2through the objective lens 22, the visible light L3 cannot be deflectedby the dichroic mirror 14. Thus, the visible light L3 does not enter thephotodetector 16, and is not therefore detected as noise by thephotodetector 16.

In short, the visible light L3 with the third spectral band B3 from theillumination light source 3 does not interfere with fluoroscopy, andhence can continue to be emitted during fluoroscopy, as well as at apreliminary stage of fluoroscopy. Since the observation window 4 cantransmit the visible light L3 with the third spectral band B3, thevisible light L3 with the third spectral band B3 is likely to enter thedark-box main body 2 through the observation window 4 from outside thedark-box main body 2. However, since the visible light L3 with the thirdspectral band B3 does not interfere with fluoroscopy as described above,the visible light L3 does not adversely affect fluoroscopy even if itenters the dark-box main body 2 through the observation window 4.

During fluoroscopy, the observer may wish to adjust the positionalrelationship between the specimen A and the fluoroscopy unit 5 whilechecking on the monitor (not shown) a fluorescence image acquired withthe photodetector 16. For this purpose, the observer can performadjustment work while clearly seeing, through the observation window 4,the specimen A and the examination head 6 which are brightly illuminatedwith the visible light L3 with the third spectral band B3 emitted fromthe illumination light source 3.

Consequently, unlike with the known method, blind adjustment in adarkroom is not required according to this embodiment, and hence anannoying repeated procedure of turning ON and OFF the illuminating lightin the darkroom can be avoided.

In the dark box apparatus for fluoroscopy 1 according to thisembodiment, the baffle plate 26 provided in the dark-box main body 2prevents the visible light L3 emitted from the illumination light source3 from directly reaching the observation window 4. Therefore, theobserver is prevented from looking directly at the illumination lightsource 3. Because of this, the observer is not too dazzled to see theinterior of the dark-box main body 2, which would occur if the observerlooked directly at the illumination light source 3.

Furthermore, according to this embodiment, the optical unit 9 includingthe excitation light source 11 is arranged outside the dark-box mainbody 2. For this reason, the temperature in the dark-box main body 2 isprevented from rising due to heat emission of the excitation lightsource 11. This is advantageous in preventing the specimen A frombecoming dry and maintaining stable examination conditions.

Although this embodiment has been described by way of the third spectralband B3, which is shorter than the first spectral band B1 of theexcitation light L1 and the second spectral band of the fluorescence L2,alternatively, a spectral band B3′ that is longer than the firstspectral band B1 and the second spectral band B2 may be adopted, asshown in FIG. 2. In this case, it is sufficient to set the transmittancecharacteristic of the observation window 4 to cover a spectral bandincluding the spectral band B3′.

In addition, the illumination light source 3 may be provided with afilter-switching unit 27 for switching the spectral band B3 of thevisible light L3 to be emitted.

When examination is to be performed using the fluoroscopy unit 5 withthe wavelength of the excitation light L1 switched, the filter-switchingunit 27 is operated to switch the spectral band B3 of the visible lightL3 to be emitted by the illumination light source 3, thereby allowingthe wavelength of the excitation light L1 to be selected more flexibly.

A dark box apparatus for fluoroscopy 30 according to a second embodimentof the present invention will now be described with reference to FIG. 3.

The same components in this embodiment as those used in the dark boxapparatus 1 according to the first embodiment shown in FIG. 1 aredenoted by the same reference numerals, and thus will not be described.

Referring to FIG. 3, the dark box apparatus for fluoroscopy 30 accordingto this embodiment includes a dark-box main body 31 in place of thedark-box main body 2 of the dark box apparatus for fluoroscopy 1according to the first embodiment. The dark-box main body 31 is notprovided with the observation window 4 in the dark-box main body 2 tocompletely block extraneous light. Instead, a camera (photography unit)32 is provided in the dark-box main body 31 and a monitor 33 is providedoutside the dark-box main body 31.

The camera 32 has a field of view large enough to allow both theobjective lens 22 of the fluoroscopy unit 5 and the specimen A to bephotographed simultaneously in the dark-box main body 31. Furthermore,the camera 32 is arranged opposite to the illumination light source 3 onthe other side of the baffle plate 26 and is prevented from directlyphotographing the illumination light source 3. The camera 32 may berealized by a CMOS camera or a CCD camera. A CMOS camera has low powerconsumption, and is advantageous in terms of energy efficiency.

In the dark box apparatus for fluoroscopy 30 according to thisembodiment, with the above-described structure, the interior of thedark-box main body 31 can be observed using the camera 32 and themonitor 33, even during fluoroscopy, with the aid of the illuminationlight source 3 emitting light L3 (not limited to visible light in thiscase) having the third spectral band B3, which does not interfere withfluoroscopy. This allows the observer to finely adjust the positionalrelationship between the fluoroscopy unit 5 and the specimen A duringfluoroscopy, in the same manner as in the first embodiment.

With the dark box apparatus for fluoroscopy 30 according to thisembodiment, the dark-box main body 31 may be provided with a pluralityof cameras 32. This allows images from the plurality of cameras 32 to beobserved by switching the screen on the single monitor 33. In thismanner, the specimen A can be examined from a plurality of angles. Thisis advantageous in adjusting the positional relationship between thefluoroscopy unit 5 and the specimen A more accurately and easily.

Furthermore, in a case where the specimen A is a living organism,various items of information, such as vital information and temperatureinformation, from several sensors (not shown in the figure) attached tothe specimen A and the dark-box main body 31 may be simultaneouslydisplayed on the monitor 33.

As shown in FIG. 4, a dark box apparatus for fluoroscopy 30′ where thecamera 32 is integrated with the monitor 33 by means of a wall surface31 a′ of a dark-box main body 31′ or the camera 32 is provided with themonitor 33 in some way may also be employed. In this case, the camera 32is mounted so as to face the interior of the dark-box main body 31′,whereas the monitor 33 is mounted so as to face the exterior of thedark-box main body 31′, namely, opposite to the camera 32. In thismanner, the observer of the monitor 33 can see into the dark-box mainbody 31′ as if he or she were looking into the dark-box main body 2through the observation window 4 of the dark box apparatus forfluoroscopy 1 according to the first embodiment. Therefore, the observercan perform adjustment of the examination head 6 and the stage 8 throughremote operation while intuitively recognizing the movement directionand the amount of movement of the examination head 6 and the stage 8 onthe monitor 33.

In addition, as shown in FIG. 4, the camera 32 provided or integratedwith the monitor 33 may be secured on the wall surface 31 a′ of thedark-box main body 31′ with bellows 34. The position of the camera 32can be adjusted through deformation of the bellows 34, and a region tobe examined can be adjusted within the deformation range of the bellows34.

A fluoroscopy system 40 according to a third embodiment of the presentinvention will now be described with reference to FIG. 5.

The same components in this embodiment as those used in the dark boxapparatuses 1 and 30 according to the first and second embodiments aredenoted by the same reference numerals, and thus will not be described.

Referring to FIG. 5, a fluoroscopy system 40 according to thisembodiment includes the above-described fluoroscopy unit 5 and a darkbox apparatus for fluoroscopy 41. As shown in FIG. 5, the dark boxapparatus for fluoroscopy 41 is provided on a dark-box main body 42 suchthat a door 43 can be opened and closed with a hinge 44. The dark-boxmain body 42 is provided with an open/closed sensor 46 that can detect adetection member 45 on the door 43 when the door 43 is closed.

Furthermore, an excitation-light control unit 47 is connected to theopen/closed sensor 46. When the door 43 is opened, the open state of thedoor 43 is detected by the excitation-light control unit 47 and theopen/closed sensor 46. Since the detection member 45 goes out of thedetection range of the open/closed sensor 46 at this time, theexcitation light source 11 is turned OFF and stops the excitation lightL1 from being emitted.

In the fluoroscopy system 40 according to this embodiment, with theabove-described structure, when the door 43 is closed, the detectionmember 45 is detected by the open/closed sensor 46 and a signalindicating a closed state is sent to the excitation-light control unit47. As a result, the excitation-light control unit 47 allows theexcitation light source 11 to emit the excitation light L1. In the samemanner as with the dark box apparatus for fluoroscopy 1 according to thefirst embodiment, the positional relationship between the fluoroscopyunit 5 and the specimen A is adjusted through the observation window 4with the aid of the illumination light source 3 while fluoroscopy of thespecimen A is in progress.

In this state, for the fluoroscopy system 40 according to thisembodiment, when the door 43 of the dark-box main body 42 is opened forsome reason, the open/closed sensor 46 is actuated to detect that thedoor 43 is in an open state. As a result, the excitation-light controlunit 47 stops the excitation light source 11 from emitting theexcitation light L1. In this manner, the excitation light L1 isprevented from leaking out of the dark-box main body 42. Consequently,fluoroscopy with the door 43 opened, which would cause extraneous lightwith various spectral bands to enter the dark-box main body 42, isprevented. Therefore, photographing a fluorescence image with a highdegree of noise is avoided.

In this embodiment, the excitation light source 11 is prevented fromemitting the excitation light L1 depending on the open/closed state ofthe door 43. Alternatively, a shutter (not shown in the figure) may beprovided in front of the excitation light source 11 and the excitationlight L1 may be turned ON/OFF according to open/close state of theshutter. Furthermore, when the door 43 is opened, the excitation lightL1 may be blocked and the illumination light source 3 may be turned OFF.As a result of the illumination light source 3 being turned OFF whilethe dark-box main body 42 is observed through the observation window 4,the observer is informed of an open state of door 43 earlier.

Furthermore, a timer that is operatively associated with the operationof the open/closed sensor 46 may be provided to record information aboutthe period of time for which the door 43 is open or to display suchinformation on the monitor.

In this embodiment, the excitation light source 11 is disabled when thedoor 43 is open. Instead of or in addition to this, an operation controlunit 48 connected to the open/closed sensor 46 may be provided, as shownin FIG. 6. The operation control unit 48 is connected to, for example,the raising-and-lowering mechanism 7 of the examination head 6 or to thedriving device of the stage 8, so that when the open/closed sensor 46detects the closed state of the door 43, the operation speed in a closedstate, such as the speed of the raising-and-lowering mechanism 7 in thedark-box main body 42, is preferably set to lower than the speed in anopen state.

Although the interior of the dark-box main body 42 can be observedthrough the observation window 4, the amount of information acquiredfrom the observation window 4 is restricted, and therefore, by settingthe operation speed such as the speed of the raising-and-loweringmechanism 7 to a lower value while the door 43 is closed, the risk ofdamage to the specimen A and to the objective lens 22 due tointerference between the specimen A and the objective lens 22 can bereduced.

1. A dark box apparatus for fluoroscopy comprising: a dark-box main bodyenclosing a specimen and a fluoroscopy unit for illuminating thespecimen with excitation light with a first spectral band and fordetecting fluorescence with a second spectral band generated by thespecimen; an illumination light source disposed in the dark-box mainbody to emit light with a third spectral band different from the firstspectral band and the second spectral band; and an observation windowdisposed on the dark-box main body, the observation window being capableof transmitting light with a fourth spectral band which includes atleast part of the third spectral band and does not include the firstspectral band and the second spectral band.
 2. The dark box apparatusfor fluoroscopy according to claim 1, wherein the illumination lightsource is disposed at a location such that the illumination light sourceis not directly visible from outside through the observation window. 3.A dark box apparatus for fluoroscopy comprising: a dark-box main bodyfor blocking entry of extraneous light by enclosing a specimen and afluoroscopy unit for illuminating the specimen with excitation lightwith a first spectral band and for detecting fluorescence with a secondspectral band generated by the specimen; an illumination light sourcedisposed in the dark-box main body to emit light with a third spectralband different from the first spectral band and the second spectralband; a photography unit disposed in the dark-box main body tophotograph the specimen illuminated by the illumination light source andthe fluoroscopy unit; and an image display unit disposed outside thedark-box main body to display an image acquired by the photography unit.4. The dark box apparatus for fluoroscopy according to claim 3, whereinthe illumination light source is disposed at a location such that lightemitted from the illumination light source is not directly incident uponthe photography unit.
 5. The dark box apparatus for fluoroscopyaccording to claim 3, wherein a camera including the photography unitand the image display unit is provided on a wall surface of the dark-boxmain body such that the photography unit faces inward and the imagedisplay unit faces outward.
 6. The dark box apparatus for fluoroscopyaccording to claim 5, further comprising: a bellows member between thewall surface of the dark-box main body and the camera, the bellowsmember supporting the camera so that the camera is movable relative tothe wall surface.
 7. The dark box apparatus for fluoroscopy according toclaim 1, wherein the illumination light source includes awavelength-switching mechanism for switching a spectral band of emittedlight.
 8. The dark box apparatus for fluoroscopy according to claim 3,wherein the illumination light source includes a wavelength-switchingmechanism for switching a spectral band of emitted light.
 9. Afluoroscopy system comprising: a fluoroscopy unit for illuminating aspecimen with excitation light with a first spectral band and fordetecting fluorescence with a second spectral band generated by thespecimen; and the dark box apparatus for fluoroscopy according to claim1, wherein the dark-box main body includes: a door for opening andclosing the dark-box main body; an open/closed sensor for detecting anopen/closed state of the door; and an excitation-light control sectionfor stopping emission of excitation light from the fluoroscopy unit whenthe open/closed sensor detects that the door is opened.
 10. Afluoroscopy system comprising: a fluoroscopy unit for illuminating aspecimen with excitation light with a first spectral band and fordetecting fluorescence with a second spectral band generated by thespecimen; and the dark box apparatus for fluoroscopy according to claim1, wherein the dark-box main body includes: a door for opening andclosing the dark-box main body; an open/closed sensor for detecting anopen/closed state of the door; and an operation control section fordecreasing an operation speed of the fluoroscopy unit when theopen/closed sensor detests that the door is closed.
 11. A fluoroscopymethod for emitting excitation light with a first spectral band from afluoroscopy unit onto a specimen and for examining fluorescence with asecond spectral band emitted from the specimen, the method comprisingsteps of: enclosing the specimen and the fluoroscopy unit with a darkbox; emitting light with a third spectral band different from the firstspectral band and the second spectral band in the dark box; andmanipulating the specimen or the fluoroscopy unit from outside the darkbox while observing light with the third spectral band outside the darkbox through an observation window, disposed in the dark box, capable oftransmitting light with a fourth spectral band which includes at leastpart of the third spectral band and does not include the first spectralband and the second spectral band or through a photography unit disposedin the dark box.